Tuesday, September 6, 2011

Soil Remediation

What Is It?

Soil remediation is the term given to any process that is used to revitalize soil in an effective way. There are many different strategies and techniques for this. Specialists will determine which technique is best according to the type of soil, the level/type of contamination, the surrounding flora and fauna, and a number of other factors. Sometimes multiple operations are needed to effectively deal with the contamination. Water and air remediation are two other processes that fall under the umbrella of environmental remediation.

Assessment and Testing:

Before any treatment options are explored, the extremely vital testing phase needs to take place. This is where soil and/or water samples are taken which will reveal the level of contamination, the type of chemicals present and the type of processing options available to solve it. Common compounds found include various types of heavy metals and hydrocarbons.

Excavation and Dredging:

If the contamination is thought to be untreatable due to very high levels of contamination, then the soil is simply transported elsewhere and replaced with clean, new soil. This process is known as excavation and dredging. The unusable soil is then taken to a landfill and simply dumped.

Pump and Treat:

Pump and treat is another common technique whereby the toxic ground water is removed and then purified through filtering and treatment. The soil itself then undergoes the exact same process rendering it clean as well. The ground water and soil are then re-united, hopefully restoring it’s original state.

Chemical Treatment:
Certain chemicals are proven effective in the field of soil renewal. This is one of the many techniques that may be used in soil remediation: Slotted PVC is be placed throughout the bottom of a prepared pit and connected to vent pipes in each corner. Air is later blown down these pipes to supply the existing bacteria with the oxygen that is vital to the process. Then special chemicals are applied to the soil by a high-pressure spray system. The initial application of the chemical is being applied as a conveyor drops the soil into the pit. While the soil is evenly distributed throughout the pit in layers by heavy machines, a heavier application of chemicals are applied and worked in. While the degradation time will vary depending on environmental factors, certain chemicals have been proven to be an effective and outstanding tool, allowing the naturally occurring bacteria to rapidly decompose the hydrocarbon contamination. When circumstances warrant, bacteria and nutrients may be added to the soil to expedite it.

The Future:

New technological breakthroughs are pushing the envelope of soil remediation every day. New techniques and methods are being tested all over the world which will hopefully one day create a cheap, 100% effective and fast way to clean damaged soil. This will allow massive amounts of land previously declared dangerous or unusable to be re-purposed for animals, new buildings, parks, farms and who knows what else. This will also go a long way to restoring the very fragile water table in certain parts of the world.